What’s next: Prosecutors for special counsel Robert Mueller recommended Manafort serve 19 to 24 years in prison for the crimes. Manafort also faces federal court sentencing in Washington, D.C., on March 13.

More than 18 months of special counsel Robert Mueller's investigation has netted 199 criminal charges, 37 indictments or guilty pleas, and 4 prison sentences.

Driving the news: Roger Stone, a longtime Trump associate, was indicted last month on 7 counts, including lying to Congress, witness tampering, and obstructing an official proceeding. He has now been fully restricted from speaking publicly about the case, after he posted an Instagram photo of Judge Amy Berman Jackson with a crosshairs symbol near her head.

2017

Oct. 30: Manafort and his business partner Rick Gates are indicted on 12 counts, including conspiracy against the U.S. and money laundering.

The same day, Trump's former campaign adviser, George Papadopoulos, pleads guilty to making false statements to the FBI regarding his contact with Russian leadership. He later claims he misled agents to protect the president.

Dec. 1: Former national security advisor Michael Flynn pleads guilty to "willfully and knowingly [making] false, fictitious and fraudulent statements and representations" to the FBI regarding his conversations with Russian ambassador to the U.S., Sergey Kislyak.

The charges against both Manafort and Kilimnik include conspiracy and obstruction of justice in an alleged attempt to influence other testimonies. Mueller also charges Manafort with conspiracy to launder money, acting as an unregistered foreign agent and lying to authorities against Manafort.

Aug. 21: Manafort is found guilty by a Virginia jury on eight counts of fraud.

That same day, Cohen pleads guilty in a Manhattan courtroom to eight counts related to tax fraud and campaign finance violations related to the Southern District of New York's investigation. Over the next few months, Cohen reportedly spent more than 70 hours in interviews with the special counsel.

Sept. 14: Manafort pleads guilty to charges brought by the special counsel and enters into a "cooperation agreement."

Nov. 8: Attorney General Jeff Sessions submits his resignation at the request of President Trump. Sessions' chief of staff Matthew Whitaker, a public critic of the Mueller investigation, is appointed acting AG.

Dec. 4: Mueller files a memo recommending no prison time for Flynn, citing his "substantial assistance" and cooperation in the special counsel's investigation.

Dec. 7: Prosecutors from New York’s Southern District recommend a "substantial term of imprisonment" for Michael Cohen for campaign finance and tax violations, as well as lying to Congress, despite his cooperation with the investigation.

Mueller also filed a memo on Cohen stating that he is not taking a position on what amount of prison time Cohen should serve, but said "any sentence of incarceration" the court in New York recommends would be "appropriate."

Mueller filed a second documentrevealing that Manafort lied to the FBI and the Special Counsel's Office about his contact with administration officials, a Russian political consultant, a wire transfer, and information related to another DOJ investigation.

Dec. 12: Michael Cohen was sentenced to three years in prison on charges related to campaign finance violations, tax evasion and lying to Congress. In his guilty plea, Cohen claimed then-candidate Donald Trump directed him in 2016 to pay hush money to two women who alleged affairs.